Weird reform/upgrade?

[Poddster]

In the attached save I am about to play the Coral Sea map. I have two dead scout planes: One ki-15 and one Aichi E13A.

If I try and buy a H8K I'm presented with an odd pop-up: It claims I have a dead one and can reform it... It does this twice, for each H8K I buy and consumes one of the two dead scout planes. Doing so costs 50 each time.

If I manually reform, both Aichi E13A and the ki-15 cost 20 to reform, and 40 to convert to H8K (not listed as a "green" upgrade path)

So I can upgrade them for cheap if they're dead and not of the same type. Is this working as designed?
(Also it happens if I try and buy two Aichis)

(Note the save is a .saz -- the forums doesn't allow .saz or .sav so I just renamed it?)